Table 2.

Tobacco cigarette and EC use characteristics

	Former smoker	Current smoker		Never smoker
	N = 237 N (%)	N = 64 N (%)	p-value*	N = 19 N (%)
Tobacco cigarette use
Age started smoking
< 18 years	153 (65)	46 (73)	0.15	N/A
18 or older	84 (35)	17 (27)
Daily cigarette consumptiona
0–10 cigarettes	30 (13)	28 (47)	<.01	N/A
11–20 cigarettes	98 (43)	20 (33)
More than 20 cigarettes	98 (43)	12 (20)
EC use
Length of EC use
About 6 months or less	36 (15)	17 (27)	0.04	6 (32)
About 1 year	47 (20)	17 (27)		9 (47)
Between 1 and 2 years	83 (35)	19 (30)		3 (16)
2 years or more	71 (30)	11 (17)		1 (5)
EC use per day
1–3 times per day	12 (5)	2 (3)	0.52	4 (21)
4 or more times per day	219 (95)	62 (97)		15 (79)
Use different nicotine concentrations
Yes	36 (15)	8 (13)	0.59	1 (5)
Primary nicotine concentration (mg/ml)
Missing	44 (19)	24 (38)	0.04	7 (37)
Low <6	73 (31)	18 (28)		9 (47)
Medium 6–15	90 (38)	18 (28)		2 (11)
High >15	30 (13)	4 (6)		1 (5)
Primary motive for using ECs
Aid to quit smoking	100 (42)	25 (39)	0.12	NA
Cheaper than tobacco cigarettes	8 (3)	6 (9)		0 (0)
Healthier than tobacco cigarettes	89 (38)	21 (33)		1 (5)
Enjoyment	30 (13)	6 (9)		13 (68)
Other	10 (4)	6 (9)		5 (26)
Plan to reduce the nicotine in ECs
Yes	184 (78)	53 (83)	0.66	6 (31)
Time from wakening to first EC
Less than 30 min	143 (62)	39 (64)	0.64	3 (16)
Plan to quit using ECs
Yes	94 (40)	29 (45)	0.72	4 (21)

Abbreviations: EC = Electronic cigarette, N = Total number, NA = not applicable

*p-values from Chi-square or Fisher Exact tests for comparisons between current and former smokers

^aFor former smokers, daily cigarette consumption is for use prior to smoking cessation